How could we build a neural network that is invariant to permutations of the inputs?
Here is a few that might be what you are looking for:


Deep Sets, https://papers.nips.cc/paper/6931-deep-sets.pdf
BRUNO: A Deep Recurrent Model for Exchangeable Data, https://arxiv.org/pdf/1802.07535.pdf
Deep Learning with Sets and Point Clouds, https://openreview.net/pdf?id=HJF3iD9xe
Permutation-equivariant neural networks applied to dynamics prediction, https://arxiv.org/pdf/1612.04530.pdf